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Biomedical subjects

N L Bartlett

Publications and source records attributed to N L Bartlett.

18 recordsLinked to original sources

Dose-escalated cyclophosphamide, doxorubicin, vincristine, prednisone, and etoposide (CHOPE) chemotherapy for patients with diffuse lymphoma: Cancer and Leukemia Group B studies 8852 and 8854.

BACKGROUND: To address the feasibility and outcome of moderate dose intensification with granulocyte-colony stimulating factor (G-CSF) for patients with aggressive non-Hodgkin lymphoma (NHL), the Cancer and Leukemia Group B (CALGB) conducted two studies evaluating dose-escalated cyclophosphamide and etoposide in the cyclophosphamide, doxorubicin, vincristine, prednisone, etoposide (CHOPE) regimen. METHODS: Eligibility criteria included histologically documented, diffuse small cleaved, diffuse mixed, diffuse large cell, or immunoblastic lymphoma, Stage III--IV or bulky Stage II disease, and an ECOG performance status of 0--1. CALGB 8852, a group-wide study, accrued 227 patients: 120 patients in the pilot study to determine the maximum tolerated dose (MTD) without G-CSF and 107 in the pilot study of dose-escalated CHOPE with G-CSF. CALGB 8854, a limited-institution, Phase I study, enrolled 38 patients and determined the MTD of CHOPE with G-CSF to be used in CALGB 8852. The MTD in both studies was defined as the dose at which 50% of patients had 1) Grade 4 neutropenia or thrombocytopenia lasting 7 days or more, or 2) Grade 3--4 hemorrhage or nonhematologic toxicity (excluding alopecia, nausea, and emesis), or 3) were prevented from receiving 100% of drug on Day 22. RESULTS: The MTD of CHOPE without G-CSF was cyclophosphamide 1000 mg/m(2) on Day 1 and etoposide 100 mg/m(2) on Days 1--3 with doxorubicin 50 mg/m(2) on Day 1, vincristine 1.4 mg/m(2) (maximum, 2 mg) on Day 1, and prednisone 100 mg on Days 1--5. With the addition of G-CSF at 200 microg/m(2) on Days 5--19, the MTD was cyclophosphamide 1500 mg/m(2) and etoposide 160 mg/m(2) on Days 1-3 with standard doses of doxorubicin, vincristine, and prednisone. Increasing the dose of G-CSF from 200 microg/m(2) to 400 microg/m(2) did not allow for further dose escalation. The primary toxicity in all cohorts was neutropenia. Four toxic deaths occurred on CALGB 8852. The 5-year failure free survival (FFS) and overall survival (OS) rates for eligible patients on CALGB 8852 were 31% (95% confidence interval [95%CI], 23--39) and 48% (95%CI, 40--57), respectively. The 5-year FFS and OS rates for eligible patients on CALGB 8854 were 34% (95%CI, 17--52) and 51% (95%CI, 33--70), respectively. CONCLUSIONS: Moderate dose escalation with G-CSF is feasible. However, response and survival rates of patients who receive dose-escalated CHOPE, even with the addition of G-CSF, appear similar to the rates reported with standard-dose CHOP.

Adult↗

Cyclin D1 as an aid in the diagnosis of mantle cell lymphoma in skin biopsies: a case report.

Mantle cell lymphoma (MCL), an uncommon and aggressive form of non-Hodgkin lymphoma, typically involves lymph nodes. It usually only secondarily involves extranodal sites. We describe an unusual case of a MCL that presented and relapsed in the earlobes. Light microscopic findings were initially regarded as suggestive of small lymphocytic lymphoma, although subsequent analysis of fresh tissue by flow cytometry led to the diagnosis of MCL. Retrospective application of a broad panel of recently developed markers suitable for analysis of routinely processed tissue yielded results that also permitted a diagnosis of MCL. If these results had been available at the time of initial presentation, they would have obviated the need for rebiopsy. Greater awareness not only of the phenotypic criteria by which lymphomas are classified but of the lymphoma markers available for evaluation of routinely processed tissue should facilitate the accurate diagnosis of diseases like MCL and minimize the risk of misdiagnosis as an indolent disorder.

Biomarkers, Tumor↗

Hodgkin's disease: prognostic factors and short-course regimens.

Both topics discussed in this review, prognostic factors and short-course regimens for Hodgkin's disease, have been the focus of recent research with the goal of developing tools and treatments that will result in the highest cure rates with the least long-term sequelae. A new "prognostic score" for advanced-stage Hodgkin's disease and several potential prognostic factors, including soluble CD30, soluble interleukin-2 receptor, activated cytotoxic T-lymphocytes, and Epstein-Barr virus, are discussed. Preliminary reports of short-course chemotherapy regimens with and without radiotherapy for all stages of Hodgkin's disease are summarized.

Antineoplastic Combined Chemotherapy Protocols↗

Assessment of the stanford V regimen and consolidative radiotherapy for bulky and advanced Hodgkin's disease: Eastern Cooperative Oncology Group pilot study E1492.

PURPOSE: This study was performed, in a multi-institutional setting, to evaluate the efficacy and feasibility of the Stanford V chemotherapy regimen plus radiotherapy to bulky Hodgkin's disease sites. PATIENTS AND METHODS: A two-stage design was implemented in a phase II study involving 47 patients with bulky mediastinal stage I/II or stage III/IV Hodgkin's disease. Twelve weeks of the Stanford V chemotherapy regimen were given with consolidative radiotherapy (36 Gy) to lymph nodes >/= 5 cm and/or macroscopic splenic disease. Treatment was administered in one of five institutions participating in the Eastern Cooperative Oncology Group. RESULTS: With a median follow-up of 4.8 years, 45 patients are alive and 40 have been continuously disease-free. The estimated freedom from progression was 87% at 2 years and 85% at 5 years. Overall survival was 96% at 2 and 5 years. There was one death from Hodgkin's disease and one death from an M5 acute leukemia. Six of seven relapsed patients received high-dose therapy and autologous stem-cell transplantation. The freedom from second progression for the seven relapsed patients was estimated at 98% at 3 years. CONCLUSION: Stanford V chemotherapy and consolidative radiotherapy to bulky disease is effective in bulky and advanced Hodgkin's disease in a multi-institutional setting. On this basis, an Intergroup study comparing doxorubicin, bleomycin, vinblastine, and dacarbazine with the Stanford V regimen has been initiated.

Adolescent↗

Treatment advances in non-Hodgkin's lymphoma.

Non-Hodgkin's lymphomas (NHL) encompass a heterogeneous group of lymphoid malignancies with varying natural histories and prognoses. Recent classifications for NHL have defined distinct lymphoma entities based on morphology, immunophenotype, genetic features, clonal cell lineage and clinical features. These new, more precise classifications and characterizations of NHL will be essential in developing new targeted therapies. However, for this brief review, we will continue describe NHL primarily as indolent or aggressive. Treatment options for patients with indolent, but generally incurable, lymphomas include a 'watch and wait' approach, single agent alkylators, nucleoside analogues, combination chemotherapy, immunotherapy with monoclonal antibodies, radiolabelled monoclonal antibodies, or interferon (IFN). Vaccine therapy for indolent lymphomas is currently under intense investigation. For aggressive lymphomas, combination chemotherapy remains the standard of care. Major advances in the management of aggressive lymphomas include validation of the international prognostic index and clarification of the role of high-dose therapy with bone marrow or stem cell transplant in patients with relapsed aggressive lymphomas. Multiple randomised pilot trials of high dose therapy as initial therapy for aggressive lymphomas have shown conflicting results and await confirmatory studies.

Antibodies, Monoclonal↗

T-small lymphocyte disorders.

Less than 2% of all lymphoproliferative diseases are indolent or small T-cell disorders, and include T-cell chronic lymphocytic leukemia (CLL)/prolymphocytic leukemia (PLL), large granular lymphocyte (LGL) leukemia, and mycosis fungoides (MF). T-PLL has an aggressive clinical course characterized by high lymphocyte counts, marked hepatosplenomegaly, anemia, thrombocytopenia, and median survival times less than 1 year. The majority of cases are associated with abnormalities of chromosome 14. T-CLL probably represents a small cell variant of T-PLL with a similar aggressive course and similar cytogenetics. T-LGL leukemia is a clonal disorder of CD3+, cytotoxic T lymphocytes. Common clinical features include neutropenia, anemia, splenomegaly, and recurrent bacterial infections. The prognosis is dictated by the severity of the neutropenia, with 10-year actuarial survival rates greater than 80%, and most deaths related to sepsis. A small subset of LGL leukemias have a natural killer (NK) phenotype, are refractory to treatment, and result in multiorgan failure and death in a few months. Mycosis fungoides (MF), the most common of the small T-cell disorders, is a cutaneous T-cell lymphoma with a chronic course, often extending over decades, with most patients eventually succumbing to infection. The small T-lymphocyte disorders represent a rare, diverse group of diseases, which generally have an indolent course, but are not curable.

Chromosome Aberrations↗

Bone marrow staging in patients with non-Hodgkin's lymphoma: is flow cytometry a useful test?

BACKGROUND: Flow cytometric analysis of bone marrow often is used as an adjunct to morphologic evaluation in the staging of patients with non-Hodgkin's lymphoma (NHL). The goal of this study was to define objectively the benefit of flow cytometry in this setting. METHODS: The authors reviewed retrospectively all bone marrow specimens submitted between January 1992 and December 1994 to the Washington University Department of Pathology for flow cytometric immunophenotyping to rule out NHL. Results of morphologic examination and flow cytometry were reviewed independently and the ability to detect bone marrow involvement compared. RESULTS: Two hundred and seventy-three bone marrow specimens from 190 patients with an established diagnosis of NHL were submitted for flow cytometric analysis at initial presentation, restaging, and/or recurrence. Morphologic evaluation was negative in 69%, positive in 23%, and equivocal in 8%. Flow cytometry was negative in all but 1 morphologically negative bone marrow specimens and 40% of morphologically involved bone marrow specimens. Two of 23 morphologically equivocal bone marrow specimens were positive by flow cytometry. An additional 86 specimens were obtained to rule out NHL in patients without an established diagnosis of NHL. The majority of patients had a history of human immunodeficiency virus infection, cytopenia, or unexplained fevers. Morphologically, one specimen was involved with NHL, 5 were equivocal, and 80 were negative. All specimens were negative by flow cytometry. CONCLUSIONS: In this study, flow cytometric analysis improved the detection of NHL in bone marrow in only 3 of 273 samples, 2 of which were suspicious morphologically. Flow cytometry of bone marrow aspirates has a limited role in the routine staging and follow-up of patients with an established diagnosis of NHL.

Bone Marrow Examination↗

Splenic pathology in myelodysplasia: a report of 13 cases with clinical correlation.

Splenomegaly is uncommon in myelodysplasia (MDS) and, although cytopenias may be severe, therapeutic splenectomy is rarely performed. We report the histologic, histochemical, and immunophenotypic findings of nine cases of surgical splenectomy and four postmortem spleens from MDS patients. Four histologic patterns were identified: one dominated by erythrophagocytosis, one characterized by red pulp plasmacytosis, one with extramedullary hematopoiesis as the only salient finding, and one with marked red pulp expansion caused by a monocytic proliferation. Wright-Giemsa and histochemical stains were performed on touch preparations in three cases and played a critical role in the precise subclassification of one MDS patient's hematologic disorder, which ultimately proved to be chronic myelomonocytic leukemia. Splenectomy led to sustained improvement of cytopenias in three cases, but did not eliminate transfusion dependence for the remaining patients. Three splenectomy cases exhibited clustered Leder-negative mononuclear elements: two of these patients experienced disease progression to refractory anemia with excess blasts in transformation or acute myelogenous leukemia during post-splenectomy follow-up, whereas none of the three splenectomy patients without clustered mononuclear elements did. We conclude that splenomegaly in MDS usually reflects the sequelae of dyspoiesis rather than evidence of a proliferative phase, that clustering of Leder-negative large cells may correlate with either a substantial monocytic component or, possibly, increased risk of disease progression, and that the spleen can provide diagnostic as well as prognostic information in MDS patients with splenomegaly.

Adult↗

Assessment of knowledge about cancer pain management by physicians in training.

This survey assessed the knowledge of physicians in training about the pharmacology of opioid analgesics and the benefits of palliative radiation therapy in the management of cancer pain. Eighty-one trainees at the Washington University Medical Center completed a questionnaire that addressed the palliative care of a hypothetical patient with metastatic non-small cell lung cancer. The questions addressed were 1) opioid selection, 2) conversion of parenteral to oral morphine, 3) management of opioid toxicities, 4) opioid addiction, and 5) efficacy of radiation therapy. The results demonstrated that few physicians in training were familiar with the stepwise progression of analgesic selection outlined in the World Health Organization (WHO) guidelines. When asked to convert a parenteral dose of morphine to an equivalent dose of a controlled-release preparation, 75% calculated a dose that was less than one-third the correct dose; only four (5%) calculated the dose correctly. Trainees were familiar with the management of opioid toxicities. They were unfamiliar with the palliative benefits of radiation therapy. Although 41% recognized that complete relief of pain could be achieved in 50%-60% of patients, most (70%) predicted that maximum pain relief would be seen within the first month, and 98% predicted maximum benefit by 12 weeks. Although cancer pain management has been highlighted in the lay and medical literature, physicians in training still demonstrate deficiencies in their knowledge about the pharmacology and bioequivalency of the opioid and the benefits of radiation therapy. Published guidelines for the management of cancer pain need to be disseminated to all medical personnel caring for patients with cancer.

Analgesics, Opioid↗

Treatment of aggressive histology lymphoma.

The recent phase III intergroup trial showed no improvement in outcome with the use of second- and third-generation regimens for primary treatment of aggressive lymphomas. Efforts are now underway to significantly intensify therapies for patients with high-risk aggressive lymphoma by utilizing hematopoietic growth factors or autologous peripheral blood stem cells. Preliminary results show minimal or no benefit to intensification of standard regimens using growth factor support alone. However, high-risk patients who achieve a complete remission with standard therapy appear to benefit from consolidative bone marrow transplantation. Results of a novel, dose-intense regimen, which administers several non-cross-resistant drugs as high-dose single agents in rapid succession, may provide a promising alternative for primary therapy of high-risk aggressive lymphoma. New regimens incorporating high-dose cytarabine for patients with poor prognosis, small noncleaved-cell lymphoma seem to improve survival. The ability to effectively tailor therapy for subgroups of patients with aggressive lymphoma depends on the continued identification of clinical and biologic prognostic factors to compliment the International Prognostic Factors Index.

Antineoplastic Agents↗

Brief chemotherapy, Stanford V, and adjuvant radiotherapy for bulky or advanced-stage Hodgkin's disease: a preliminary report.

PURPOSE: Although survival rates have improved for patients with bulky and advanced-stage Hodgkin's disease (HD), current treatments entail substantial acute morbidity and risks for late effects such as infertility, second malignancies, and cardiopulmonary toxicities. A novel, brief chemotherapy regimen (doxorubicin, vinblastine, mechlorethamine, vincristine, bleomycin, etoposide, and prednisone [Stanford V]) was designed to shorten the duration of treatment, significantly reduce cumulative doses of alkylating agents, doxorubicin, and bleomycin, and maintain dose-intensity (DI). This brief chemotherapy was combined with radiation therapy (RT) to bulky disease sites. METHODS: Since May 1989, 65 previously untreated patients were treated for stage II HD with bulky mediastinal involvement (n = 21) or for stage III or IV HD (n = 44). Patients received weekly chemotherapy for 12 weeks. Consolidative RT was given to the first 25 patients to sites of initial bulky disease or radiographic abnormalities that persisted after chemotherapy; in the remaining 40 patients, RT was limited to bulky disease (adenopathy > or = 5 cm and/or macroscopic splenic nodules defined by computed tomography [CT]). RESULTS: With a median follow-up period of 2 years, actuarial 3-year survival rate is 96% and failure-free survival (FFS) rate is 87%. The 3-year FFS rate is 100% for stage II patients with bulky mediastinal disease and 82% for patients with stage III to IV disease. There were no treatment-related deaths. In a preliminary analysis on a subset of patients, female and male fertility appears to be preserved. CONCLUSION: These preliminary results indicate that the Stanford V chemotherapy regimen with or without RT is well-tolerated and effective therapy for bulky, limited-stage, and advanced-stage HD. Less cumulative exposure to alkylating agents, doxorubicin, and bleomycin and limited use of radiation is expected to decrease risks for second neoplasms and late cardiopulmonary toxicity. Based on these results, the Stanford V chemotherapy with or without RT regimen deserves further study in the context of a randomized clinical trial.

Actuarial Analysis↗

Phase I trial of doxorubicin with cyclosporine as a modulator of multidrug resistance.

PURPOSE: To study the effects of cyclosporine (CsA), a modulator of multidrug resistance (MDR), on the pharmacokinetics and toxicities of doxorubicin. PATIENTS AND METHODS: Nineteen patients with incurable malignancies entered this phase I trial. Initially patients received doxorubicin alone (60 or 75 mg/m2) as a 48-hour continuous intravenous (i.v.) infusion. Patients whose tumors did not respond received CsA as a 2-hour loading dose of 6 mg/kg and a 48-hour continuous infusion of 18 mg/kg/d with doxorubicin. Target CsA levels were 3,000 to 4,800 ng/mL (2.5 to 4.0 mumol/L). Doxorubicin doses were reduced to 40% of the prior dose without CsA, and then escalated until myelosuppression equivalent to that resulting from doxorubicin alone was observed. Doxorubicin pharmacokinetics were analyzed with and without CsA. RESULTS: Thirteen patients received both doxorubicin alone and the combination of doxorubicin and CsA. Mean CsA levels were more than 2,000 ng/mL for all cycles and more than 3,000 ng/mL for 68% of cycles. Dose escalation of doxorubicin with CsA was stopped at 60% of the doxorubicin alone dose, as four of five patients at this dose level had WBC nadirs equivalent to those seen with doxorubicin alone. Nonhematologic toxicities were mild. Reversible hyperbilirubinemia occurred in 68% of doxorubicin/CsA courses. The addition of CsA to doxorubicin increased grade 1 and 2 nausea (87% v 47%) and vomiting (50% v 10%) compared with doxorubicin alone. There was no significant nephrotoxicity. Paired pharmacokinetics were studied in 12 patients. The addition of CsA increased the dose-adjusted area under the curve (AUC) of doxorubicin by 55%, and of its metabolite doxorubicinol by 350%. CONCLUSION: CsA inhibits the clearance of both doxorubicin and doxorubicinol. Equivalent myelosuppression was observed when the dose of doxorubicin with CsA was 60% of the dose of doxorubicin without CsA. Understanding these pharmacokinetic interactions is essential for the design and interpretation of clinical trials of MDR modulation, and should be studied with more potent MDR modulators.

Adult↗

Follicular large-cell lymphoma: intermediate or low grade?

PURPOSE: To evaluate the benefit of anthracycline-based chemotherapy, identify prognostic factors, and determine the value of the International Prognostic Factors Index for patients with follicular large-cell (FLC) lymphoma. PATIENTS AND METHODS: This retrospective study includes 96 patients with FLC lymphoma treated at Stanford University Medical Center between 1969 and 1991. Fifty-five patients received doxorubicin plus cyclophosphamide-containing chemotherapy regimens, 21 patients received other chemotherapy regimens, 15 patients received radiotherapy only, and five patients received no initial therapy. Thirty-four patients had stage I or II disease and 62 patients had stage III or IV disease. RESULTS: With a median follow-up duration of 5.2 years (range, 1 to 18), the actuarial 5- and 10-year overall survival rates were 75% and 54%, with actuarial 5- and 10-year freedom from progression (FFP) rates of 53% and 42%, respectively. Patients treated with chemotherapy regimens that contained both doxorubicin and cyclophosphamide had a superior actuarial 10-year FFP rate (55% v 25%, P = .06) and overall survival rate (65% v 42%, P = .04) compared with patients treated with other chemotherapy regimens. Only one patient treated with doxorubicin plus cyclophosphamide relapsed after 3 years. In the multivariate analysis, discordant lymphoma and treatment with chemotherapy regimens not containing both cyclophosphamide and doxorubicin predicted for worse FFP and overall survival rates. In addition, poor performance status and increasing areas of diffuse histology predicted for a worse survival, while anemia and male sex predicted for a worse FFP. The age-specific International Index was useful in predicting outcome; however, few patients with FLC lymphoma had high-risk features. CONCLUSION: The plateau in FFP implies that patients with FLC lymphoma enjoy sustained remissions after standard anthracycline-based chemotherapy. FLC lymphoma should continue to be approached as an intermediate-grade lymphoma with curative intent.

Actuarial Analysis↗

MACOP-B +/- radiation therapy for diffuse large cell lymphoma. Analysis of the Stanford results according to prognostic indices.

BACKGROUND: The efficacy and toxicity of the MA-COP-B regimen were assessed after outstanding results were reported in diffuse large cell lymphoma (DLCL) by the Vancouver group. The results are reported according to several proposed prognostic indices, including the recent International Prognostic Factors (IPF) Project. METHODS: Forty-seven patients with untreated DLCL received MACOP-B chemotherapy. Thirty patients, most of whom had bulky disease, also received consolidative radiation therapy (RT). Patient characteristics include median age of 42 years, Stage III/IV (57%), bulky or symptomatic Stage II disease (43%), elevated lactic dehydrogenase (81%) and at least one extranodal site (72%). RESULTS: At a median follow-up of 3.3 years, overall survival was 57% and freedom from progression (FFP) was 52%. The 3-year FFP data were related to tumor extent: 74% for limited stage versus 38% for extensive disease. These data correlated well with four prognostic indices reported in the literature. The IPF index accurately identified low-, intermediate-, and high-risk subgroups. CONCLUSIONS: Patients with limited or low-risk DLCL have an excellent prognosis with MACOP-B +/- RT. These results do not support the use of consolidative high-dose therapy and bone marrow transplantation in patients with limited disease, even if bulky or accompanied by an elevated lactic dehydrogenase. Compared to historical CHOP data, MACOP-B +/- RT does not appear to improve outcome for those patients with poor prognostic features, most of whom will fail. The IPF index is a simple, accurate method of distinguishing high-risk patients who require new therapeutic initiatives.

Adult↗

Serum markers in germ cell neoplasms.

Innovations in the treatment of testicular cancer, including surveillance of clinical stage I patients and curative chemotherapy for disseminated disease, have increased the need for sensitive ways to stage and monitor patients, both during and after therapy. Serum tumor markers, in combination with radiographic studies, have significantly improved our ability to evaluate and treat patients with seminomas and NSGCT. Elevated AFP and BHCG levels provide prognostic information at diagnosis, indicate persistent disease following orchiectomy or RPLND, and signal a recurrence after chemotherapy. Significantly delayed clearance of markers during chemotherapy often indicates persistent disease. Serum markers help define the duration of therapy, thus minimizing the substantial toxicities often associated with curative chemotherapy. Despite these advances, areas of concern remain. A small percentage of patients with NSGCT and the majority of patients with seminoma have undetectable levels of AFP and BHCG. The search for additional sensitive and specific serum markers in these cases has not been wholly successful. LDH, PLAP, and BFP occasionally serve as useful markers in seminoma but suffer lack of specificity. In addition, normal postoperative or postchemotherapy serum marker levels do not always ensure complete remission. This is difficult clinically when residual masses persist following therapy. Resection is always required to rule out persistent disease. The next decade may reveal additional useful serum tumor markers and potentially new imaging techniques incorporating antimarker antibodies to differentiate necrotic tissue from active disease.

Biomarkers, Tumor↗

Biodistribution and dosimetry results from a phase III prospectively randomized controlled trial of Zevalin radioimmunotherapy for low-grade, follicular, or transformed B-cell non-Hodgkin's lymphoma.

UNLABELLED: Radiation dosimetry studies were performed in patients with non-Hodgkin's lymphoma (NHL) treated with 90Y Zevalin (90yttrium ibritumomab tiuxetan, IDEC-Y2B8) on a Phase III open-label prospectively randomized multicenter trial. The trial was designed to evaluate the efficacy and safety of 90Y Zevalin radioimmunotherapy compared to rituximab (Rituxan, MabThera) immunotherapy for patients with relapsed or refractory low-grade, follicular, or transformed NHL. An important secondary objective was to determine if radiation dosimetry prior to 90Y Zevalin administration is required for safe treatment in this patient population. METHODS: Patients randomized into the Zevalin arm were given a tracer dose of 5 mCi (185 MBq) (111)In Zevalin (111indium ibritumomab tiuxetan) on Day 0, evaluated with dosimetry, and then administered a therapeutic dose of 0.4 mCi/kg (15 MBq/kg) 90Y Zevalin on Day 7. Both Zevalin doses were preceded by an infusion of 250 mg/m(2) rituximab to clear peripheral B-cells and improve Zevalin biodistribution. Following administration of (111)In Zevalin, serial anterior and posterior whole-body scans were acquired and blood samples were obtained. Residence times for 90Y were estimated for major organs, and the MIRDOSE3 computer software program was used to calculate organ-specific and total body radiation absorbed dose. Patients randomized into the rituximab arm received a standard course of rituximab immunotherapy (375 mg/m(2) weekly x 4). RESULTS: In a prospectively defined 90 patient interim analysis, the overall response rate was 80% for Zevalin vs. 44% for rituximab. For all patients with Zevalin dosimetry data (N=72), radiation absorbed doses were estimated to be below the protocol-defined upper limits of 300 cGy to red marrow and 2000 cGy to normal organs. The median estimated radiation absorbed doses were 71 cGy to red marrow (range: 18-221 cGy), 216 cGy to lungs (94-457 cGy), 532 cGy to liver (range: 234-1856 cGy), 848 cGy to spleen (range: 76-1902 cGy), 15 cGy to kidneys (0.27-76 cGy) and 1484 cGy to tumor (range: 61-24274 cGy). Toxicity was primarily hematologic, transient, and reversible. The severity of hematologic nadir did not correlate with estimates of effective half-life (half-life) or residence time of 90Y in blood, or radiation absorbed dose to the red marrow or total body. CONCLUSION: 90Y Zevalin administered to NHL patients at non-myeloablative maximum tolerated doses delivers acceptable radiation absorbed doses to uninvolved organs. Lack of correlation between dosimetric or pharmacokinetic parameters and the severity of hematologic nadir suggest that hematologic toxicity is more dependent on bone marrow reserve in this heavily pre-treated population. Based on these findings, it is safe to administer 90Y Zevalin in this defined patient population without pre-treatment (111)In-based radiation dosimetry.

Antibodies, Monoclonal↗